The Right Reason
by haupetals
Summary: Marco Diaz was in deep trouble. Unbeknownst to him, he wasn't alone. Starco oneshot, Prom-ish themed.


**A/N: It's my first official oneshot on Fanfiction, and I have to say I was pretty nervous about posting it, but I'm excited about it too! This is your standard Starco story, with fluff throughout, general awkwardness, Marco being Marco, Star being Star, and internal discourse. Gotta love it. Also, Star and Marco are 17 to 18 years old in this, just to make things clear. Hope you enjoy the story, and let me know how you liked/disliked it!**

 **Star Vs. The Forces of Evil and its characters belong to Disney, not me. Rated T for certain content at the end, *cough* kissing *cough*.**

* * *

Moving his food around with his fork on his dinner plate, the brunette sighed, averting his eyes from his chattering family. Marco Ubaldo Diaz was in deep, deep trouble. The kind of deep where it's like you've been treading deep water for ten minutes and you're not an Olympic swimmer so you've been getting rather tired and you feel like you're going to drown in all the deepness surrounding you, so you're panicking and it's all a mess of anxiety and hopelessness—

He raised his gaze to meet Star Butterfly's gleaming azure ones, and his heart skipped a beat. Yeah. That kind of deep trouble.

Everything went wrong when he inadvertently put an end to paying special attention to Jackie Lynn Thomas..and started paying closer attention to Star Butterfly, his best friend, instead. His crush on Jackie sort of faded away when he realized he didn't really know her. At all. He remembered how he felt that day everything changed, when he was actually talking to Jackie without feeling much hyperventilation. It was casual, normal—something he'd dreamed of for years.

"—Wait, so you ran into him?" Marco snorted, and Jackie winced, her nose scrunching up in sheepish embarrassment.

"Yeah–well, sort of! I _totally_ wasn't paying attention, and I ran right over his foot," The beach-waved blonde laughed, and Marco laughed with her, shaking his head, his heart racing—he was talking to Jackie Lynn Thomas, he was talking to Jackie Lynn Thomas. They were friends now, anyways, but Marco had felt a little flustered around her regardless.

"He started swearing at me, all kinds of words that to be honest—I'd rather _not_ mention and then—" She kept talking and Marco's chestnut eyes glanced over her shoulder, soon widening visibly. Star was laughing and blushing, her stunning blue eyes adorably crinkling at the corners with her infectious giggles, but it wasn't with Oskar. It wasn't with Justin, or Ferguson, or Janna, or Alfonzo—it was with the new kid. Tanner Hall. Marco's eyes narrowed. _Tanner Hall_.

Tanner Hall, the new guy that everyone couldn't stop talking about. Tanner Hall, who was great at pretty much everything. Tanner Hall, the incredibly good-looking humorous everything-any-girl-could-ever-want-in-a-guy Tanner Hall.

He moved into the Echo Creek district a few weeks ago, and became quite popular almost instantly. Tanner had auburn hair, grey eyes, a splash of freckles across his nose with deep olive skin—Star described him as some fine specimen who crawled out of a cinnamon-autumn-scented rainbow geyser. Marco's breath hitched as Star flashed a smiling Tanner a brilliant grin, her entire face lighting up as she talked. She could make anyone fall in love with her with only a smile. Hell, her wand even lit up as she leaned in, speaking with Old Spice about who knows what. Marco's eyebrows knit together.

" _Marcooooo_ -" Jackie waved her hand in front of his face, snickering slightly. Marco snapped out of his jealous musings (wait—jealous?) and met Jackie's smug gaze. "I said I'll see you in Chemistry tomorrow, okay?" She smiled knowingly before skating off.

The brunette stared after her with a perplexed, shocked expression, before he heard Tanner talking to Star again, and Marco shifted right back to where he was before, but this time he tried to lean against the lockers casually.

"—was thinking maybe we could get together sometime? Sort of like a date..?" Marco watched Tanner ask Star. Tanner's gaze looked completely entranced, and it looked like he couldn't even wipe the smile off of his stupid freckled face. Star's eyes widened and she nodded vigorously, her grip tightening on her wand.

"Yes, I would _love_ that!" The blonde sang in reply, bouncing on her heels, her face flushing. Marco nearly slipped onto the floor because it felt like his heart almost fell out of his chest. Why did he feel like this, though? Why did it hurt so terribly? Star was his best friend, nothing more. He should be happy for her...right? Marco was spacing out again, a pained expression on his face, and he forced himself to tune into the conversation as he wiped himself off.

"Meet me at my house this Friday!" Star invited Tanner. "I'll have the movies and popcorn all ready for us." She winked, nudging him. Tanner nodded with another stupid grin before walking off, a skip in his step.

Thinking back to a few moments before, Marco tried to distract himself with the fact that he talked to Jackie Lynn Thomas, but it didn't work. He stared at Star from across the hall, who was biting her wand in excitement. Why wasn't it working? He always liked Jackie, he always liked her, why were _Star's_ eyes in the back of his mind instead of Jackie's? Why did, when given the choice, Marco prefer to hold _Star's_ hand instead of Jackie's? Star spotted him across the hallway and was immediately at his side, singing about her date with stupid-Tanner-autumn-cinnamon-or-whatever-spice-Hall.

Marco couldn't breathe. No way. _No way_. He liked Star. He had a crush on—Her fingers curled around his arm to get his attention and he felt heat rise to his cheeks.

"Marco! He asked me on a date! I said—I said yes of course, you know, kind of in a chill way, like this—" Star leaned against the wall and nodded with a wide grin plastered on her face. "And now he's coming over Friday after school," She sighed dreamily, fiddling with her wand in her energetic hands. Marco tried to smile, but it turned out to look like more of a grimace.

"That's.. _great_ , Star!" He choked out. He desperately wished she'd let go of his arm and stop looking at him so he could breathe for a second. Star deflated and stared at him worriedly, only coming closer, leaning in. Marco's heart rate quickened. He could see the light flecks of green in her concerned eyes she was so close.

"Marco—are you alright? Did things go okay with Jackie?" She squeezed his arm.

"Yeah, Star, we actually had a full, normal conversation." Marco reassured with as much enthusiasm as he could muster. Her gaze softened and she smiled, tilting her head.

"That's wonderful Marco! Maybe you can ask her out this Friday, too, if you keep at it!" Star grinned. Marco nodded in a daze. He didn't want to ask Jackie out.

"Marco."

He didn't want to ask Jackie out, not ever. He wanted to—

"Marco!"

He was yanked out of that horrid, distant memory that happened months ago and he straightened, his grasp on his utensil tightening visibly.

Star watched him from across the table with that beautiful smile of hers, winding up spaghetti noodles with her fork. "You okay?" His parents watched him with the similar, smiling expressions, and Marco nodded, swallowing thickly as he took a swig of his water.

"Super." He replied blandly.

The princess continued explaining how incredibly amazing her five-month relationship was going with Tanner, and Marco speared a meatball on his plate rather violently, shoving it into his mouth. He eventually got up without a word, shuffling into the living room. Why was Tanner so cool anyways? Tanner didn't have anything Marco didn't have. Tanner even knew a little karate, but his yellow belt would never compare to Marco's black belt that he earned only months ago. The brunette huffed, frowning weakly as he sat on the couch, it wasn't Tanner's fault. He didn't mean to be so rude to the guy, but Marco, as much as he hated to admit it, was jealous. He wished he'd only realized how he felt about Star sooner before Tanner waltzed into the picture. Seeing Star with Tanner felt like getting stabbed thirty seven times in the chest. Every little hand hold, longing glance, hug—Marco shuddered at the memories, when he was practically screaming at them internally to stop. He even walked in on them kissing. _Kissing_. Lips connecting, and he swore he heard Star sighing softly and _ugh._ It was brief and Star told Marco after he had witnessed it that she never really went too far with Tanner, but her reassurance didn't help. At all.

"—he's probably going to be here _iiiinnn abouuuut_ —" A knock at the door sounded and Star scrambled out of her seat, her silver rainbow-sequined prom dress flouncing around her. "Now!"

Marco had already beat her to the door, staring Tanner down with an expression of disapproval. "Tanner! Hey!" Star pushed past her best friend, laughing nervously, her hand resting on his chest to keep him from kicking Tanner to the moon.

She wouldn't be surprised if Marco was capable of doing it with _that_ kind of muscle—the blonde hesitated from the thought, chewing on her lower lip nervously. Tanner was a great boyfriend. Standard, funny, well-rounded, a great kisser, good at self defense, toned, an uneventful, perfect boyfriend for her crazy mess of a life. But she was crushing on her best friend. Hard. For a while. Whenever Star kissed Tanner, she imagined Marco instead, and so on. It wasn't healthy. It wasn't right. Marco was always like a brother to her, she was positive he never felt the same as she did. That's why she had to distract herself with Tanner. She _had_ to get over Marco Diaz. She'd never be able to kiss him, hold his hand in that romantic sort of way, hug him for however long she wanted, cuddle up on the couch with him while they watched action movies—Tanner was the only one who ever wanted to do those things with her, and Marco? He'd never want that. She knew him too well.

Tanner took her hand, pulling her away from the door, a dorky grin on his face. "You look stunning! Are ya ready to go?" Star managed to smile excitedly before turning back to Marco, her heart shattering at his expression. He hadn't asked anyone to prom. The blonde invited him to tag along with girls who hadn't been asked, but he always refused for some dumb Marco reason.

"You sure you don't want to go with Ponyhead or anyone? I could call her up! She's a party!" The princess laughed, and Marco smiled slightly, a smile that made Star's heart thud longingly in her head.

"That's okay Star. She's a _little_ too wild of a dancer for me." Marco stammered, laughing awkwardly. Star did look beautiful, her sunshine-curled hair wound up into a bun, wavy ringlets framing her face while pink sequins glittered across her braided-back bangs, and her face was so naturally captivating, Marco found he couldn't stop staring at her. Tanner was lucky. Outrageously lucky. Marco blushed and cleared his throat. "Er—" He glanced from Star to Tanner. "Have fun."

Star stared concernedly as he quickly shut the door, leaving her alone with Tanner. She almost left Tanner at the doorstep to hang out with Marco instead (in all honesty, she'd much rather do that, but darn it all she had obligations to keep).

She managed to keep a happy, excited demeanor while they drove to prom, Tanner belting out some song about shutting up and dancing, but someone kept flickering in the back of her mind. Get out of my head, get out of my head. She was going to have a great time with Tanner tonight. Nothing was going to stop her from spending time with Marc— _Tanner_. Shoot. Star glanced out the window into the whirring night to keep her thoughts from _him_ , yet everything she saw reminded her of Marco in some way. A hoodie store, the dojo, the fortune cookie place—she twirled a stray hair from her bun around her finger, biting the inside of her cheek. "Ohh no." She whispered. Marco Diaz, Marco Diaz, Marco Diaz—Marco-get-out-of-my-head-Diaz, she tried to chant in her mind. It was no use.

Star was still into that hoodie-wearing-fanny-pack-loving dork, and she _had_ to tell him, no matter how scared she was of rejection...and of leaving Tanner. He was really sweet, but he wasn't Marco. He could never compare to that hunk of a man. The school approached in the distance, and her heart leapt. She couldn't do this. Star's breath hitched, and she began unbuckling her seat belt. Her date glanced at her and back to the road, slowing down, a confused expression on his face.

"Babe, what are you doing?" Tanner asked, raising an eyebrow.

"Stop the car!" She yelled, squeezing her eyes shut. Star pressed a hand to the dashboard. The vehicle screeched to a stop at the side of the road and she exhaled, relieved.

Tanner was staring at her like she was crazy, and Star couldn't blame him—she sort of _was_ out of her mind. Taking a leap of faith was hard. A lot harder than fighting monsters, studying for that math test, all of it—but it was all for Marco. She returned Tanner's gaze with an apologetic stare.

"Listen, Tanner—you're...you're great but—" Star winced, biting her lip. "I can't do this anymore. I don't feel anything more than friendship with you—no matter how good of a kisser you are, or how nice you are, or how fun this senior prom is going to be—or-or any of it...I'm sorry." The blonde admitted weakly, fishing her wand out of her dress pockets. Tanner still looked shocked, but the hurt in his storm-grey eyes made her sick. "I'm sorry," Star squeaked, fumbling with the door handle.

Star got out of the car and slammed the door, kicking off her high heeled shoes, holding her wand in the air. A part of her felt horrible for what she was doing but the other half of her felt like the super cool and strong female lead in one of those romance movies she and Marco would watch occasionally. Still, it didn't make her feel any better about it, but Star couldn't deny how anxious she was to see how this turned out.

"Returnius Et Fastidum!" She yelled, and flashed back to her balcony at home in a bright pink light.

He sighed, staring at the cold, taunting concrete of Star's balcony in thought. Why he came out here to think, or hang around, or wait while Star went places without him, Marco had no idea. He knew it was sort of pathetic, since he was in love with her, after all. Thank goodness she'd never catch him wallowing in his self pity here—a bright light made him wince and he gazed, wide eyed ( _of-course-this-had-to-happen-of-course-she's-here-while-i'm-creepily-sitting-cross-legged-on-her-balcony_ ). Star stood, clearly breathless, holding onto her wand with both hands nervously. Her cerulean eyes were as wide as saucers to find him just _sitting_ there, but she quickly recovered.

She was also barefooted as she stomped over to him, and Marco scrambled to his feet, swallowing, her expression completely unreadable.

"Why don't you have any shoes?" He blurted out.

The princess, confused for a moment, laughed nervously, blushing, making the small pink hearts on her cheeks radiate. Marco had never seen her blush around, well, _him_ before, so it caused his heart rate to quicken. "I come back early from prom, possibly the most important, most anticipated thing in any teenager's life here on Earth, and all you can ask is why I don't have any shoes?" Star asked teasingly, coming even closer to him, backing him up against the side wall, her wand tumbling out of her fingers. It hit the ground with a clatter.

"I—Well—Star, you-you could have cut up your feet or—your wand fell out of your hands, by the way—I dunno—or I supposed you forgot something—here.." Marco stammered, his heart a zipping hummingbird as she gazed into his eyes with a small grin curling her lips. His nervous face softened.

"Why did you leave prom early...?" Marco paused, looking down at her. "Tanner?" He reminded, worried that she had gotten hurt.

Star's shoulders slackened and she took a step away from Marco, much to his disappointment. "I.." She rubbed her arm, her lips forming into an infuriatingly adorable pout that Marco couldn't stop staring at. "I left him. I made him stop the car. I left him, Marco. You can call me horrible for doing that but—" She straightened, pivoting around to face him directly, a rather weak smile on her face. Even so, her azure eyes held determination. "I don't care. I think I did it for the right reason.." Star took his hand, lacing her fingers through his and then she was stepping towards him again, causing his cheeks to burn a brilliant crimson.

He exhaled shakily, the cold wall against the back of his gray t-shirt. Marco couldn't focus. Her hand was in his and she was a mere centimeters from him, he could just kiss her right now, but his head was spinning and he couldn't _focus_. What could he focus on? Well. He found it quite easy to focus on her lips. "What right reason..?" Marco breathed, his eyes darting back up to Star's only to see her staring at his lips as well.

Marco couldn't remember who leaned in first, but then their lips were brushing and soon-after pressing against the other, and Star had curled her legs around his waist, her fingers running through his hair while they kissed. Marco's hands rested on her back to steady her. Star sighed his name against his lips, tugging a fistful his hair gently and goosebumps ran down Marco's spine. Their kisses became more desperate and unfocused, needing. Marco would pull away for a second to breathe before connecting his lips with hers again, and Star would make some inaudible noise that drove Marco nearly insane. This wasn't treading water in the deep trouble he had found himself in. This was completely letting go and drowning. Marco found that he couldn't care less. They parted after that long-but-also-brief moment, breathlessly, both staring at the other in obvious shock, their faces clearly flushed.

"Marco, I—"

"Star—"

"I love you." They said in unison, pausing for a second of surprise before spilling into loud, relieved, infectious laughter. Star rested her forehead against his, and Marco stepped away from the wall with her and the skirt of her incredibly puffy dress in his arms, spinning around, making the pair laugh even more.

Eventually, their laughter died down and Star finally answered his question, still comfortably latched onto him, her fingers playing with his hair. "You were the right reason," She whispered with a wide grin.

Marco snorted, kissing her gently, making her giggle breathlessly. "Cheeseball."

* * *

 _the end._


End file.
